Date: Wed, 16 Jul 1997 14:22:50 -0700 (MST) From: Terry Lambert <terry@lambert.org> To: cbrown@aracnet.com Cc: smp@csn.net, smp@FreeBSD.ORG Subject: Re: HEADS UP: EISA cards. Message-ID: <199707162122.OAA01516@phaeton.artisoft.com> In-Reply-To: <33CC9317.9C7588D8@earthling.net> from "Chris Browning" at Jul 16, 97 01:23:35 am
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> Why would you not want to abandon the 8254? Why not use the APIC's > timer? I would imagine that it was put there for this purpose when > running in full symetric mode. This is a HAL issue. The problem, I suspect, is that we Steve wants the kernel to run on non-APIC machines as well (correct me if I'm wrong), and the kernel expects timer services. Ideally, you would want to abstract the service provision from the hardware selected to provide the service. To do this would require abstracting it at the "this IC provides these services" hardware level... in other words a HAL. I suspect that this will be necessary for the Alpha port (it was necessary for the non-ISA bridged Alpha ports of the FreeBSD console code to NetBSD -- also a general problem of "what hardware will provide these services that the console expects the kernel to provide for it"; specifically, the PCaudio stuff has to modularly drop out when there is no coupling to the speaker wave generator of the IC providing the timer services). > Also, why would you not want to program the IOAPIC to handle > "this" as normal INTs? Most likely because the INT will happen whether you want it to or not. 8-|. Regards, Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.
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